Objective-C:用命令行参数的格式对文件进行IO操作

//  main.m

//  03-copyFile

//  Created by ma c on 15/8/24.

//  Copyright (c) 2015年. All rights reserved.

#import <Foundation/Foundation.h>

 int main(int argc, const char * argv[])

{
    @autoreleasepool
    {
        //1、检查参数
        if(argc < 3)
        {
            NSLog(@"用法:命令行 源文件 目标文件");
            return -1;
        }


        //2.检查源文件是否存在

        NSString *file1 = [NSString stringWithUTF8String:argv[1]];

        NSString *file2 = [NSString stringWithUTF8String:argv[2]];

        

        NSFileManager *fm = [NSFileManager defaultManager];

        BOOL isDirectory = YES;
       

        if(![fm fileExistsAtPath:file1 isDirectory:&isDirectory])
        {
            NSLog(@"源文件不存在");
            return -1;
        }
        else
        {
            if(isDirectory)
            {
                NSLog(@"不能拷贝目录");
                return -1;
            }


            //3.判断目标文件是否存在
            if(![fm fileExistsAtPath:file2 isDirectory:NULL])
            {
                [fm createFileAtPath:file2 contents:nil attributes:nil];
            }
            else
            {
                NSLog(@"是否要覆盖文件? 'y' or 'n'");
                char answer = getchar();
                if(answer != 'y')
                {
                    return -1;
                }
            }

     

            //4.文件拷贝
            NSFileHandle *in = [NSFileHandle fileHandleForReadingAtPath:file1];

            NSFileHandle *out = [NSFileHandle fileHandleForWritingAtPath:file2];
            if(in && out)
            {
                while(YES)
                {
                    NSData *data = [in readDataOfLength:100];
                    if(!data || [data length]<=0)
                    {
                        break;
                    }
                    [out writeData:data];
                }
            }
            else
            {
                NSLog(@"文件打开失败");
            }

            

            //5.关闭文件
            [in closeFile];
            [out closeFile];
        }
    }
    return 0;
}